1. Field of the Invention
Embodiments of the present invention relate to the design of layouts used in semiconductor manufacturing. More specifically, embodiments of the present invention relate to a method and an apparatus for identifying locations in a layout of an integrated circuit (IC) chip that are susceptible to fabrication issues.
2. Related Art
In the manufacture of IC chips, minimum feature sizes have been continuously decreasing. The current minimum feature size is smaller than the wavelength of visible light used in the conventional optical imaging system. Accordingly, it has become increasingly difficult to achieve reasonable fidelity, which is often expressed in resolution and depth of focus, between a designed layout and the shapes of actual fabricated circuit elements. Existing reticle enhancement technologies (RET's), such as optical proximity correction (OPC), phase-shifting masks (PSM's), and sub-resolution assist features (SRAF's), are becoming inadequate to solve fabrication issues on the nanometer scale.
Manufacturability-aware physical design, which takes into account both yield and reliability during the physical-design process, is becoming increasingly important in bridging the gap between design and manufacturing for nanometer-scale fabrication. Many yield and reliability issues can be attributed to certain layout configurations, referred to as “process-hotspots” or “hotspots,” which are susceptible to process issues such as stress and lithographic process fluctuations. It is therefore desirable to identify and remove these process-hotspot configurations and replace them with more yield-friendly configurations.
Although it is possible to perform simulation and predict manufacturing results based on the simulation results on these physical designs, the costs of doing so on a large scale during the design process can be prohibitively high. Hence, there is a need for a technique for accurately and cost-effectively detecting process-hotspots in a given routed layout that are most susceptible to manufacturing process issues.